A thorough screening procedure to diagnose congenital coagulation disorders must start from a careful collection of the personal and family clinical history, followed by a two-step laboratory screening. The first step is aimed at detecting the most frequent and well established causes of hemorrhage by a simple battery of laboratory tests such as bleeding time, platelet count, prothrombin time and activated partial thromboplastin time. The second step is to be performed in case of a past history of bleeding, but normal first-step laboratory screening and is aimed at detecting the less frequent abnormalities of hemostasis such as factor XIII, antiplasmin, platelet factor 3, von Willebrand factor, tissue plasminogen activator and dysfibrinogenemia, to which the first-step screening tests are not sensitive.